This invention relates to devices and means by which water wave energy is reduced or dissipated to control erosion and deposition of beach sand and minimize movement of floating docking systems, and more particularly to easy to install and remove devices made from a multiplicity of modular elements.
Breakwaters, seawalls, jetties and groynes are structures intended to dissipate incoming water wave energy and to reduce or change shoreline erosion and deposition. These structures are permanent, expensive, often unsightly and have limited in effectiveness. Typically, these structures act as barriers that redirect or absorb incoming wave energy. Often this energy undermines and helps destroy these structures, or as redirected energy it continues to erode or deposit materials in other locations farther along the shoreline.
Various modular offshore systems utilizing tires or other elements have been introduced for purposes of erosion control, wave energy extraction, and the creation of artificial reefs to encourage the population of fish, crustacea and other aquatic life. These systems are constructed as groups that are rigidly anchored to the sea floor allowing for minimal movement. In particular, Bishop, U.S. Pat. No. 5,879,105 discloses a system of buoyant, hollow bodies, constructed to form islands in the form of inverted pyramids, rigidly anchored offshore to extract or disperse wave energy. These buoyant bodies are multi-faceted with solid protruding ends, that when connected together provide for a plurality of avenues arranged to extract the energy from the flowing water. Such an arrangement is only partially effective, having no specific design to break the laminar water flow into one of turbulence. The protruding ends make the individual bodies awkward to handle, stack and transport.
There is a need for a modular element that can be combined, with other elements, to form a wave energy dissipation system that has multiple recesses that will channel flowing water. When a plurality of these bodies are connected to form a wave attenuation system, the water will be channeled through a series of constrictions and voids which will dissipate the water wave energy by hydraulic resistance and friction. Critical to the effectiveness and efficiency of such a system is the need for these preferably buoyant bodies to break the laminar flow of the water into a state of turbulence. This state of turbulence increases the disorganization and chaos of the incoming water, greatly increasing the distance that individual cells of water have to travel in order to pass through the system. As these water cells have to travel farther through he system, the overall resistance to water flowing through the system is greatly increased.
The buoyant bodies are preferably designed so that they may be used in flotation, ballast or near neutral buoyancy situations with minimal or no modification. Any wave attenuation system constructed from these modules needs to accommodate different anchoring systems. The system must be easily movable to other locations and accommodate adjustments for buoyancy and flotation level.
There is also a need for the individual buoyant bodies to be easily and inexpensively manufactured. They should be light in weight, easily handled, stacked and transported. The buoyant body must be of a material that is inert and poses no threat to the environment. Further, the buoyant body and constructed wave attenuation system using a plurality of such bodies, needs to be highly versatile so that the construction of the system may be achieved in a number of different situations, e.g., a floating pontoon, the back of a boat, on the shore or even at a remote site and transported in sections to the deployment site.
The buoyant body should be of such a design that it may be used for other marine and near marine situations, e.g., support of floating docks, artificial reefs and beach creation devices.
In accordance with this invention, an apparatus and system for dissipating water wave energy and for shoreline control. Specifically it describes a wave control system including a module with a generally hollow body, a pair of opposed flanges attached to adjacent corners of the body, a pair of axially aligned mounting apertures in the flanges for connecting the body to similar bodies for forming a wave energy dissipation system, and a recess disposed between the flanges having a surface characterized by a plurality of boundary layer interrupting projections substantially disrupting any laminar flow of water past the surface and creating turbulent flow.